The Study On Enhancing 4VG Content In Wheat Beers Brewed With Caramel Malts

4-vinylguaiacol is a kind of typical characteristic flavor substance,which is generated by the metabolism of ferulic acid in malts.It can be produced both malting,wort boiling and the decarboxylation of top-fermenting yeast during fermentation,which can impart some phenolic aromas.In order to enhance the 4VG concentration in top-fermented wheat beers brewed with caramel malts,the ratios of caramel malts,mashing temperatures,boiling times,yeast strains and fermentation temperatures were investigated and some laboratory-scale and pilot-scale experiments were carried out to brew top-fermented wheat beers.By analysis of physicochemical indexes,flavor substance detection of HPLC and GC,sensory evaluation of beers and orthogonal experimental design,the optimal technology of enhancing the 4VG concentration in top-fermented wheat beers brewed with caramel malts was gained: i.e.the ratio of caramel malts was 10%,mashing temperature was 37?,boiling time was 90 minutes,top-fermenting yeast strain was No.303 and fermentation temperature was 20?.In the meantime,the results showed that yeast strains and fermentation temperatures have a notable influence on 4VG levels.